Tretinoin was co-developed by James Fulton and Albert Kligman in 1969.[2] Together, Fulton and Kligman are credited as the inventors of Retin-A.[2] Fulton was a researcher at the University of Pennsylvania at the time.[2] The University of Pennsylvania held the patent for Retin-A, which it licensed to pharmaceutical companies.[2]

Tretinoin is most commonly used as a form of acne treatment.[3] It was the first retinoid developed for this type of topical use.[citation needed] Tretinoin is the best studied retinoid in the treatment of photoaging.[4] It is used by some as a hair loss treatment [5] and is a component of many commercial products that are advertised as being able to slow skin aging or remove wrinkles.[6][7]Topical tretinoin is also used to treat and reduce the appearance of stretch marks by increasing collagen production in the dermis.[8]

The pathology of the leukemia is due to the highly proliferative immature cells; retinoic acid drives these cells to develop into functional cells, which helps to alleviate the disease.[citation needed] It is usually prescribed for 15 days every three months at about 8–10 10-mg capsules per day.[citation needed]

Successfully treating acute promyelocytic leukemia (APL) with Tretinoin was a major breakthrough in APL therapy.[11] It works in APL because the majority of cases involve a chromosomal translocation of chromosomes 15 and 17, which causes genetic fusion of the retinoic acid receptor (RAR) gene to the promyelocytic leukemia (PML) gene.[12] This fusion PML-RAR protein is responsible for preventing immature myeloid cells from differentiating into more mature cells. This block in differentiation is thought to cause leukemia. ATRA acts on PML-RAR to lift this block, causing the immature promyelocytes to differentiate to normal mature blood cells thus decreasing promyelocytes.[citation needed]

When used, dryness or increased sensitivity to sunlight of the affected skin may occur.[13] More sensitive patients may also experience redness, scaling, itching, and burning.[14] A gradual increase in the frequency and amount of tretinoin application is best, as this allows one's skin to adequately adjust to the drug. Patients should be careful to follow their physician's recommendations when beginning a round of treatment.

As this product may cause irritation, it may indirectly increase sun sensitivity and fragility of the skin.[15] Patients who are using the drug should apply moisturizer and sunscreen to reduce the chance of developing sunburn while using tretinoin.[15] Additionally, patients using tretinoin should be cautious when simultaneously using other topical medications that contain salicylic acid, resorcinol, or sulfur because these medications may potentiate the drying and possibly irritating effects of tretinoin.[16] Topical tretinoin should be avoided during pregnancy because its use has been linked to birth defects in several case reports.[17]

There is a unique complication of retinoic acid syndrome in patients with acute promyelocytic leukemia. This is associated with the development of dyspnea, fever, weight gain, peripheral edema and is treated with dexamethasone. The etiology of retinoic acid syndrome has been attributed to capillary leak syndrome from cytokine release from the differentiating promyelocytes.

It is a teratogen, and therefore can cause birth defects and tests have shown increases in fetal skull abnormalities in rats.[18] Women who are or may be pregnant, or who are seeking to become pregnant, are therefore warned against using it.[19] This teratogenic effect is caused by the interference of the exogenous retinoic acid with endogenous retinoic acid signaling, which plays a role in patterning the developing embryo. However the risks of topical tretinoin to the fetus seems to be limited.[20]

A study published by the European Respiratory Journal in 2002, suggested tretinoin can reverse the effects of emphysema in mice by returning elasticity (and regenerating lung tissue through gene mediation) to the alveoli.[21] Studies suggested this might form a promising treatment in human emphysema patients.[22] However, a newer follow-up study done in 2006 found inconclusive results ("no definitive clinical benefits") using vitamin A (retinoic acid) in treatment of emphysema in humans and stated further research is needed to reach conclusions on this treatment.[23]